Can not get statistical firecast generated

[Former Member]

Hi,

I run the statistical forecast using a batch job, I can not get statistical forecast generated for few CVC,s,

Im using Automodel2.

In the Spool request, I could see the following message:

Charact. Combination(1 Frm 1):

11 A510 509055

Following forecast profile selected: Auto Model2

Required Time for Forecast in Seconds: 0.018

Forecast values will be negative

This combination have decent history for 24 months, and Im generating monthly forecast for 18 months.

How can I get negative forecast, tried diff. ways but cannot sort out this issue.

When I run Constant model manually Im getting forecast, but not with any model.

Please help me out.

Thanks

Anna

[I813660]

Are you running it in interactive planning or using a background job?

If you are using a Background job, i'd recommend to check the aggregation level in use and if this condition gives youa proper historic values to provide a final forecasting.

Regards,

Luiz Giani

[srinivas_krishnamoorthy]

Most of the stat forecast models does not allow you to do negative number forecasting.

If you want to do forecasting for returns, then you would want to switch the negative history to positive and do the forecasting.You can have macros to switch the values to negative in a different or same key figure.

If you are seeing a negative trend in history and want to forecast, it might make sense to uplift the history with a reasonably large value, do the forecast and bring down the forecast by the same large value. All these can be done using combination of like profile and macros.

Alternatively, you can write a small development object that picks up all CVCs that have not been forecast due to negative numbers, and switch to a trend model.

[Former Member]

Hi Srinivas,

But for these CVC's I can see a nice history, then how would I get negative values? May I know the reason?

Anna

[srinivas_krishnamoorthy]

Hope you checked

http://help.sap.com/saphelp_scm2007/helpdata/en/ac/216b74337b11d398290000e8a49608/content.htm

and

http://help.sap.com/saphelp_scm2007/helpdata/en/46/a6fa5087f10488e10000000a1553f6/content.htm

The Automodel 2 uses an initialization period and does require 27 months of history at the minimum. Try to run Automodel interactively and check the trend key figure in the univariate screen. It may be due to an outlier or the product may be set up for Life cycle planning and not looking at its own history. This will be clear while doing interactive forecasting.

The other important thing is to find the results of trend and seasonal test. Are these positive in the first place. One would also want to check how Automodel 2 behaves without outlier correction.

[Former Member]

please let me know if you are seeing any negative values in the interactive planning? can you see any values in the spool list??